The present invention relates to on-board weather radar for use on aircraft or other vehicles. More particularly, the present invention relates to methods and apparatus for providing ground-based weather radar information to a pilot using on-board weather radar cockpit displays.
Weather has been identified as a cause or contributing factor to nearly 25% of aviation accidents and 35% of fatalities. Accidents occur when a chain of events leads to a failure of an aircraft system, a mistake on part of the crew piloting the aircraft, or a combination thereof. Improved levels of weather information and the use of pilot decision aids may be helpful in breaking the chain of events that leads to an accident.
In addition to creating hazardous situations, weather is a common cause of flight delays. For example, in the United States, more than 70% of delays are attributed to weather conditions. While the industry will always have some level of delay caused by extreme weather, there is a growing belief that improved weather information in the cockpit could improve efficiency for the overall system.
On-board weather radar is a tactical navigation aid that shows convective hazards for the next 15 to 30 minutes of flight. The on-board weather radar currently serves as the focus of a pilot""s awareness of the weather situation. It provides a graphical depiction of precipitation relative to the aircraft""s position. The presence of turbulence can be inferred from these reflections off of precipitation. Through the use of Doppler processing, turbulence can also be detected and displayed directly.
While the on-board weather radar has proven invaluable as a real-time source of tactical weather information, the range is limited. Additionally, the beam width of on-board weather radar increases significantly at longer ranges, making it difficult to perform fine resolution of precipitation patterns.
To enhance safety and efficiency, government and industry are attempting to improve the availability and quality of weather information available to flight crews. It is desirable to provide flight crews with weather information which has been up-linked from a ground-based weather radar system. One such ground-based weather radar system is the Next Generation Weather Radar (NEXRAD) system, the data from which is available via the Internet or other sources. These ground-based weather radar systems offer a strategic view of weather over a larger region than possible with on-board weather radar. The NEXRAD system includes ground-based radar sites distributed across the continental United States. The NEXRAD system is used to create a series of weather products, including base reflectivity, composite reflectivity, hail indices, and storm tracking information, to name a few. Generally, NEXRAD provides an excellent strategic view of the weather situation, but would likely suffer in cockpit applications from latencies due to acquisition, processing and up link.
The pilot community has expressed interest in up-linking ground-based radar images, like those available from NEXRAD, to the cockpit as has been proposed. Several industry-led programs have focused on development of applications for displaying these images in the cockpit of an aircraft. However, as mentioned earlier, these images suffer in cockpit applications from latencies due to acquisition, processing and up-link. On the other hand, the on-board weather radar images do not suffer from latencies but are of limited range. Consequently, a method that utilizes the benefits of both of these two sources would be a significant improvement in the art.
A radar displaying system and method for use in displaying weather radar information on a cockpit display of an aircraft receiving on-board weather radar information from an on-board weather radar system and ground-based weather radar information up-linked to the aircraft from a ground-based weather radar system. The information from the on-board weather radar system and the information from the ground-based weather radar system are combined to generate composite weather radar information. In response to the composite information, the cockpit display simultaneously displays both on-board weather radar imagery and ground-based weather radar imagery.